Such devices provide a rolling bearing, one of the races of which turns and the other of which is fixed, the turning race being provided with a radial leading surface intended to come into contact with the end of the fingers of the diaphragm of the clutch.
A non-turning operating element supports the rolling bearing and, when acted on by a (mechanical, electrical or hydraulic) control element, moves the bearing axially so as to cause the leading surface of the turning race to press against the diaphragm of the clutch and to actuate the clutch mechanism.
In order to limit friction wear between the fingers of the diaphragm and the turning race during clutch engagement and release operations, it is possible to fasten a wear race made of polymeric material to the turning race. For more details relating to such a wear race, reference may be made for example to patent application FR-A1-2 883 347.
In the bearing described in this earlier document, a plate crimped onto the turning race is provided to ensure retention of the wear race on the race. However, this solution has the drawback of increasing the number of components of the bearing to be manufactured, stored and assembled.